As mentioned earlier, you will sometimes find Ultra Wormholes that are pure white . This is special, because it is guaranteed to lead to an Ultra Beast. All the Ultra Beasts you can find through Ultra Warp Ride are the Ultra Beasts featured in Sun & Moon, and even better, you can catch an infinite number of them.
The Ultra Beast you will find inside is random, with some being more common than others. The following table will help you know immediately what you will get when you step into a white wormhole, and what to expect if you are hunting down a specific Ultra Beast.
|Nihilego||Ultra Deep Sea||Common|
|Buzzwole||Ultra Jungle||Common [Ultra Sun]|
|Pherosma||Ultra Desert||Common [Ultra Moon]|
|Kartana||Ultra Forest||Uncommon [Ultra Sun]|
|Celesteela||Ultra Crater||Uncommon [Ultra Moon]|
Guzzlord is the rarest of the Ultra Beasts, and any Ultra Beasts that were exclusive in Sun & Moon remain exclusive to Ultra Sun & Ultra Moon. As an interesting bit of trivia, Nihilego's Ultra Deep Sea is the same place as the Ultra Space featured in Sun & Moon.
All of the Ultra Beasts are no longer shiny locked. Once you enter the wormhole, save in front of them and you can soft reset until you get a shiny.